Reservoir simulation is an area of reservoir engineering that employs computer models to predict the transport of fluids, such as petroleum, water, and gas, within a reservoir. Reservoir simulators are used by petroleum producers in determining how best to develop new fields, as well as generate production forecasts on which investment decisions can be based in connection with developed fields.
In oil and gas reservoir simulation, a common task is to optimize a specific parameter for every well in a field (i.e., optimization at the “field level”). For example, such a task may be determining where to place each well within the field or changing reservoir simulation properties near each well so the simulated well matches historical data recorded about the well (“historical matching”). Often, these simulations employ brute force methods that attempt to optimize the parameter for all the wells in the field simultaneously, despite the fact that the parameter may be spatially dependent (i.e., changing a property of one well will affect a nearby well but will have little to no effect at a far away well). Solving for spatially-dependent parameters at a field level simultaneously may result in computational inefficiencies and a failure to fully optimize a reservoir model.
Thus, although existing approaches to reservoir simulation have been satisfactory for their intended purposes, they have not been entirely satisfactory in all respects.